Life is full of choices and trade-off decisions. Let’s say that you need to create a lookup table containing sales regions and this information doesn’t exist in the source database. You could easily create a new table in Power Query using the “Enter Data” feature, and just manually enter the sales regions. This would solve the immediate problem with very little effort, but how will the table be maintained if sales regions are added or change in the future? We could keep the list of values in an Excel file stored in SharePoint for a business owner to maintain when information changes. You could also go all the back back to the beginning of the process and load a dimension table in the source database. IT professionals might take the hardline and say that all data must flow through the data warehouse regardless of the effort and cost. Which of these is the right choice? …it depends on the scope reporting project, and the long-term ownership of the solution. Sometimes quick and convenient are OK but particularly tables that need to scale and handle larger data volumes in the future, the following guidelines are critical.
Read on for Paul’s recommended practices.